Drafting machine



J ly 19765 A. L. BAKER ETAL DRAFTING MACHINE 5 Sheets-Sheet 1 Filed Oct.25. 1961 ATTORNEY A. L. BAKER ETAL 3,196,544

Jul 27, 1965 DRAFTING MACHINE Filed 0012-. 25, 1961 3 Sheets-Sheet 2'INVENTORS f4 44 445 48 f. J3 William )Zfiause +1 AZZisterLfia/wrATTORNEY July 27, 1965 A. L. BAKER ETAL 3,196,544

DRAFTING MACHINE Filed Oct. 25, 1961 3 Sheets-Sheet 3 ATTORNEY 3,196,544DRAFTING MAtIHHQ-E Aliister L. Baker, Deuville, and William R. Krause,Secaucus, N..l., assignors. to Kcuflel & Esser Company, Hobohen, N..l'.,a corporation of New .iersey Filed Get. 25, 1961, Ser. No. 147,686 4Qlaims. (tDl. 33- 19) The present invention relates to a draftingmachine and more particularly to a drafting machine having anchor anddrafting head arms pivotally connectedtogethor at one "endwith the otherend of the anchor arm pivotally mounted on an anchor support on the edgeof a drafting board and a drafting head on the other end of the draftinghead arm, carrying a protractor and line guides which are maintainedinparallel relation by a pulley and belt system.

Heretofore draftingmachines of this type have been provided but theyhave been expensive to manufacture making them unavailable to schoolsand to students and therefore the students have not been able to takeadvantage of the increased efl-"rciency in learning and workingresulting from the use of such drafting machines. One reason for theexpense of manufacture was the skilled labor to obtain the accuracyrequired in the parts.

An object of the present invention is to provide a drafting machine ofthe pivoted, arm type which is accurate in use and can be made at a costto be available to students and to other draftsmen with limitedresources.

Another object is to provide a means to maintain the pawl for thedrafting head in an operative or inoperative position and to provideeasily operable means to restore; the operation of the pawl. A furtherobject is to provide means to change the drafting head in infiniteangular positions.

Another object is to provide means to connect a drafting machine to adrafting table to prevent theft thereof.

Other and further objects will be apparent as the description proceedsand upon reference to the accompanyline and showing in phantom outlinethe position retain:-

ing pawl in its. inoperative position out of engagement with the notcheddisc and showing the clamp for set ting intermediate angular adjustmentsand also showing the leaf spring detent operative on the control leverfor the pawl operated slide. for retaining the pawl in operative orinoperative positions.

FIG. 3 isa vertical section taken substantially on line 33 of FIG. 1showing the drafting head plate adjustably mounted in the bore of thecontrol pulley hub and showing the usual pawl releasing arrangement andthe novel push button means to restore the pawl to operative position.

FIG. 3A is a fragmentary section on line 3a-3a of FIG.v 3 showing thepawl control. bar in the cup and the pawl operating wheel.

FIG. 4 is a section taken substantially on line 4-4 of FIG. 2 throughthe infinite position clamping control toretain the drafting head inadjusted position-s.

FIG. 5 is a planview of the pivotal connection joint between the armswhich are assumed to be in superimposed position and showing theadjustment for tension- .ing the straps.

United States Patent FIG. 6 is a vertical axial section of the two armsof the drafting machine taken substantially on line 66 of FIG. showingthe means for obtaining the frictional adjustment between the arms andillustrating the bearing structure.

FIG. 7 is a plan view of the anchor end of the anchor arm showing aportion of the anchor bracket mounted on a drawing board.

FIG. 8 is an axial section taken substantially on line 88 of FIG. 7through the pivot connecting the anchor arm and the anchor bracket.

FIG. 9 is a horizontal section just above the anchor pulley taken online 99 of FIG. 8 with the arm mounting fitting removed therefrom.

FIG. 10 is a horizontal section taken substantially on line t3-ll ofFIG. 8 showing the shape of the T-groove which serves to retain theanchor pulley in fixed adjusted position.

FIG. 11 is an enlarged fragmentary circumferential section lookingtoward the axis taken along the pulley grooves of FIGS. 10 and 12through the locking screw and nut of the anchor pulley retainingstructure.

FIG. 12 is a fragmentary enlarged section taken sub stantially on line1212 of FIG. 11 showing the bolt head of the locking bolt in theT-groove.

Referring more particularly to the drawings, a drafting board 15 hasmounted thereon an anchor clamping bracket 16 which is held in positionby a clamping screw 17 and by one or more screws passing throughcountersunk screw receiving apertures in a flange 18 which anchorbracket flange is covered by a resilient rubberlike cover w securedthereto by adhesive or other means to prevent damage to line guides. Theanchor bracket includes an upstanding bearing boss 20 which isperpendicular to the clamping surface of the flange 18 and an angularlyadjustable anchor pulley 21 having an integral tubular shaft 22 whichrotatably adjustable in the anchor bearing boss 20. The anchor pulley 21is provided with a circumferential groove 23 of T-shape in radialcross-section with such groove having the flange portions removed at 24to provide for the reception of a square head 25 of an angular positionlocking bolt 26, the shank of which bolt passes through an apereutre ina lug 27 extending radially from the upper end of the anchor bearingboss 2d as clearly shown in FIGS. 10, 11 and 12. The anchor pulley 21 isprovided with a circumferential V-groove 28 on its upper surface whilean Allen head stop screw 29 is threadedly received in a threadedaperture extending between grooves 23 and 28 and such stop screw 29projects into the path of a stop lug 30 extending into a circular recessof a first fitting 31 which recess 32 receives the anchor pulley 21',said fitting having a pair of parallel tube receiving sockets 33extending tangentially in one direction. A pivot shaft 34 is fixed tosaid first fitting 31 by means of one end of such pivot shaft 34extending into a counter bore in the recess of fitting 31 and being heldin position by a screw 35 passing through the fitting wall and into athreaded bore in said pivot shaft 34. The pivot shaft 34' is retained inthe tubular shaft 22 of the anchor pulley 21 by a split ring 36 whichalso serves to retain needle bearings 37 and any suitable spacingelements in the circumferential space between the pivot shaft 34' andthe anchor pulley tubular shaft 22 to assure ease of movement of thefitting 31 and of the anchor and drafting head arms of the draft ingmachine. The pulley 21 is retained in position by the locking bolt 26and a peripherally grooved hexagonal nut 38 held in operative. positionin a broached: hexagonal opening in wrench handle 33'' having anAllen-head screw 39 threaded through the periphery of the wrench 38 andinto the groove. of the hexagonal nut- 38 so that contacting the lug 27,thereby positively retaining the.

drafting machine on the anchor clamprand also maintaining the desiredangular adjustment of the anchor pulley21.'..f a V A'second fitting40.provided.with a circular recess and a pair of sockets in'alignmentwith the sockets of by a plurality of screws, 65. Theweb of the pulley60 is spaced above the lower side of the pulley providing a recess forflange 66A of tubular flanged shaft 66, the

the first fitting is connetced by tubes 41 to the first-fitting 31, saidtubes being freely rotatable in their sockets and the structure beingmaintained in'connected. condition by the tension of the control strap42 which engages the periphery of the anchor pulley 21 and theperiphery. of'

the upper portion. of a double pulley 43. The t'ension of the controlstrap is adjusted by turnbuckle type device.

A third fitting 44 similar to the second fitting 40 and bores 40B and44B respectively. Said second and third fittings are pivotally mountedon a tubular shaft 45 extending through the bosses and through a bore inthe web offthe double pulley 43 which provides for rotation of suchdouble pulley"'43, the fittings 40 and 44 being rotatable on the.tubular shaft 45 by means of needle bearings 46 which ar e maintainedin spaced relation and in operative position by washers 47 abutting theboss of double pulley'43 and by split rings 48 in grooves of shaft 45which maintain the parts in assembled condition.

Friction washers 49 of cork are positioned against wear A headedfriction-producing bolt 52 passes through washer 51 and into the tubularshaft :45 and extending to adjacent the other end of such tubularshaft.' A flanged tubular nut 53 having a circumferential groovereceiving split ring 48 has internally threaded tubular portion thereofextending into a counterbore in the other end of tubular shaft 45 'andis threaded onto the end threads of friction-producing bolt 52. Toretain, the nut 53 against rotation'in the tubular shaft the tubularshaft a is provided with diametrically opposite pin receiving slots 54and the nut is provided with a transverse bore which receives a pin 55for preventing relative rotation of said nut with respect to saidtubular shaft 45.whereby able slot or'spaced wrench-receiving aperturesmay be provided in nut 53 to prevent rotation of the nut. assemblyduring adjustment. The bolt 52 is provided with a nylon insert 52A in atransverse bore-and such nylon insert is sufficiently long to engage thethreads of the nut 53 to retain the nut and bolt in adjusted condition.

flanged shaft being rotatable in the bore of the third pulley shaft 59.-The flanged tubular shaft is provided with a shoulder providingclearance above the tubular pulley shaftby reducing the diameter of the.shaft 66 and such'reduced portion is received in a bore, in the bottomof cup 67 which cupis. secured to the shaft by a nut 68. The cup 67 hasa radial flange 69' on the outer circumference of: the cup 67 androtatably supported on the .cup 67 and engaging the flange 69 is apawl-operating wheel 70 having a boss 71 extending along the peripheryof the cup. The cup. 67 of the pawl-operating wheel is provided withcircumferentialslots bounded by edges 72, 72.. The boss 71 hascircumferential slots defined by edges 72A and 72B spaced apart somewhatgreater than edges 72. A drafting head rotating knob handle 73 is fixedto the cup 67 by a screw 74 and such knob is provided with a centralbore and a count'erbore whichreceives a flanged push button 75 having aboss 76 slidably mounted in the bore of the knob 73 and normally urgedto the inoperative position shown in FIG. 3 by a coiled compressionspring 77, the knob being held in assembled relation by a split I ring78. A double tapered lever 79 having a fulcrum flange intermediate itsends is positioned in the passage of the flanged hollow shaft 66, oneend of said double tapered lever having a bore therein and the other'endhaving an enlargement. A pin 80 having a head at one end andanintermediate enlargement is mounted in the'bore of said one end ofsaid double tapered lever 79. V A control bar 81 having a centralaperture is positioned in the cup. 67 and extends into the slots in boss71 and cup 67 with the ends of such control bar in the path of theabutment surfaces 72 of moving the aperture in control bar 81 from theposition shown .in FIG. 3 to a displaced position as shown in phantom bydash-dot line in. FIG. 3A and moving double tapered lever 79from theposition shown to a position in which the angle extends from the upperleft to the lowerright as viewed in FIG. 3. This dotted line poi sitionof FIG. 3A corresponds to. the phantom dashdot line of the pawl in FIG.2. The boss 76 of the In normal use the pulley 43 is fitted withsufficient tightnesson tubular shaft 45 to prevent relative rotationtherebetween and merelyiby holding the'parts of the drafting machine infixedrelation the tubular shaft and the nut 53 willbe preventedfrom'rotation and frictional push button 75 is provided with, a conicaldownwardly flaring bore 76A which in the inoperative position shownpermits the double tapered lever 79 to oscillate from the full linepawlengaging position shown to a pawl releasing position. p

Mounted on the flange 676A7of the flanged hollow shaft 66 isthe draftinghead plate 83 which is'fixed to such flange 66A by suitable screws andsuch plate 83'is provided with a slot 84 in which a slide 85 is mounted,such 'slide' being urged to a retracted position by a tension ing 58therein which receives a hollow shaft 59 of a .third pulley 60providinga drafting head support, which pulley is retained in position by a splitring 61 abutting the upper surface of bushing 58 with the web of pulley60 lying beneaththe bushing, sa id pulley being provided with acircumferential rabbet which receives an annular protractor '62,'aspacing ring 63 and a notched disc 64 which-are held in fixedpositiontothe third pulley 60 spring 85A and being under the control of doubletapered lever 79 'ofwhich the enlarged lower end is received in anaperture 85B in the slide.

The aperture 85B is provided with an inwardly extending flange at itslower end thereby retaining double tapered lever 79 in operativeposition between control bar 81- and slide 85. The slide 85 isretainedfin the .slot 84 by a control lever. 86 pivotally'mounted on oneside of the slot'84 on the drafting head plate 83 and extendingunderneath the drafting head plate and under'slide 85 and operativelyconnected to the slide 85 by-a rivet 85C fixed to the slide andextending downwardly into a radial slot in the control lever 86..Additional meanssuch as a strut between the walls of theslot 84 mayassist in retaining the slide. The

other end of the slide 85 is. operatively connected by a rivet 85D fixedto and extending upwardly from the slide and received in a slot of apawl 87 which pawl is pivotally mounted on the upper surface of draftinghead plate 83. The projection tip of such pawl 87 is receivable in anyone of the notches of the notched disk 64 thereby retaining the draftinghead plate in fixed position with relation to the notched disk 64 andthe protr-actor. The control lever 86 projects beyond the other side ofslot 84 and has a tooth 86A which engages a wedge-shaped cam portion ofa leaf spring 86B, which leaf spring is adjustably secured to the undersurface of the plate 83 by suitable screws 86C passing through slots ina flange fixed to the leaf spring 8613 whereby the control lever 86 willbe retained in either of the positions shown in FIG. 2 in which theprojection of the pawl 87 is in engagement with a notch in the notcheddisk 64 as shown in full lines holding the drafting head in one of the15 adjusted positions or the pawl is in the other position as shown indash-dot lines in which the pawl is released. In the released positionthe left edge of the tooth 86A of control lever engages the right edge86D of the wedge-shaped cam portion of the leaf spring 86B therebyretaining the slide 85 against the tension of the spring 85Acorresponding to the dash-dot line position of the parts in FIG. 3Awhereby the drafting head plate 83 is free to move to any azimuthposition relative to the protractor 62.

To retain the drafting head plate in fixed position relative to theprotractor when the pawl is out of engagement with the notched disk, aflanged Z-shaped clamp element 88 (FIG, 2 .and 4) is positioned on thedrafting head plate 83 with one end of the base of the Z-shaped clampelement against the palte 83 and a flanged screw '89 passes through anaperture in the drawing head plate 88 and projects thereabove, passingthrough an enlarged aperture in the stem of the Z-shaped clamp element88 and threaded into the threaded bore of a lever 89A whereby motion ofthe lever will cause movement of the Z- shaped clamp 88. Preciseadjustment is obtained by a locking screw 89B threaded into the draftinghead plate with its head engaging the flange of flanged screw 89 to holdthe flanged screw 89 in a position so that limited movement of lever 89Awill produce the desired clampring action. Mounted on the drafting headplate 83 is an abutment 88A underlying the pr-otr-actor 62 beneath the(flange 88B of the flange-d Z-shaped clamp 88 whereby the clampingaction produced will react on the abutment 183A and avoid objectionabledistortion.

When it is desired to restore pawl 87 to operative position depressionof bottom 76 causes double tapered lever 79 to be restored to the fullline position so pawl 87 engages one of the notches in notched disk 64.It will be apparent that the movement of the push-button 75 downwardlywhen the pawl is in the full line position of FIGURE 2 causes the lever79 to move to a central position thereby moving the pawl 87 to anintermediate position in which the pawl is disengaged from the notchesof the notched disc 64 and the drafting head plate 83 can then be turnedto any desired angle to position the scale carrying lugs 90 and 91 inthe desired position, and upon release of the push-button 75 the pawlwill engage the adjacent notch of the notched disc 64.

It will be apparent that the various pulleys are connected by straps 42tensioned sufliciently by turnbuckle type tension element-s 42A tomaintain the fittings in secure assembled relation and also to assurethat there a is no slipping between the straps 42 and the pulleyscooperating therewith.

:From the above description it will be apparent that the presentinvention prOVides means to maintain the line guide scale carrying lugs90 and 91 of drafting head plate '83 in proper relation so that lineguide scales 90A and 91A carried thereby will be maintained in theirparallel relation or in a definite angular relation in accordance withthe adjustment obtained between the protractor 62 and an index 93 fixedto the drafting head plate 83 which index also serves as a housing forthe pawl 87.

It will be apparent that various changes may be made within the spiritand scope of the invention as defined in the valid scope of the appendedclaims.

What is claimed is:

l1. A drafting head structure comprising a drafting head support movablein all directions on the surface of a drawing board while maintaining aline of said support in parallel relation at all times, a shaft having abore rotatably mounted on said support, a drafting head plate rfixed tosaid shaft, a cup having a bore in the bottom thereof mounted on saidshaft in fixed relation, a pawloperating wheel having a boss projectingtherefrom rotatab-ly mounted on said cup, said cup and said boss of saidpawl-operating wheel being provided with slots therein, a drafting headrotating knob mounted on said cup, a control bar positioned in said cupand extending diametrically into the slots of said cup and boss of saidpawloperating wheel, a lever pivotally mounted in said bore of saidshaft and being connected to said control bar, a link mounted in saiddrafting head plate and connected to said lever, and a pawl operativelyconnected to said link whereby said pawl can be operated by rotation ofsaid pawl-operating wheel, a disc mounted on said drafting head supportfor cooperation with said pawl to retain said drafting head in fixedrelation to said dnafting head support, a cam push-button mounted onsaid drafting head operating knob and having its cam surface cooperablewith said lever in one direction, and a spring operable to move saidpawl into operative position with respect to said disc.

2. The invention according to claim 1 in which the cam push button ismounted for axial movement in a central bore of said drafting headrotating knob and the cam surface is concave conical embracing the saidlever pivotally mounted in said flanged shaft.

3. The invention according to claim 2 in which a yieldable detentcooperates with said pawl to retain said pawl out of engagement withsaid notched disk to permit infinite :ang-ular adjustment of said headand said cam push button will release said yieldable detent so that saidpawl can enter a notch of said notched disk.

*4. A drafting head structure comprising a drafting head support movablein all directions on the surface of a drawing boa-rd while maintaining aline of said support in parallel relation to all times, a shaft having abore rotatably mounted on said support, a drafting head plate fixed tosaid shaft, a lever pivotally mounted in the bore of said shaft, a linkmounted on said drafting head plate and connected to said lever, a pawlmounted on said drafting head plate and connected to said link, a discfixed to said drafting head support and cooperable with said pawl toretain said drafting head in fixed relation to said support, a campush-button mounted for axial movement relative to said shaft and havinga cam surface cooperable with said lever to move said lever in onedirection, and yieldable means operable to move said pawl into operativeposition with respect to said disc.

References (Zited by the Examiner UNITED STATES PATENTS 2,243,734 5/41Euban-ks 33-793 2,25 6,445 9/ 41 Wiederm'ann 3379. 3 2,266,862 12/ 41Cunningham 248- 3 61 2,289,126 7/42 Keufiel 3379 2,381,382 1 0/ 43Euban'ks 33-793 2,347,625 4/44 Wiederm ann 3'3-79.3 2,377,429 6/45Ketting 33--79.3 2,43 8,220 3 /48 Kettin g 3 3--79.3 2,4645 3/49 Ketting3379.'3 2,612,694 10/ 5 2 Vaughan 33--79.3 2,663,344 12/ 5 3 Burdi-ck 1517 2,917,267 12/59 Riddle 248-361 FOREIGN PATENTS 6,91 7 1/57 Germany.

ISAAC LISAN'N, Primary Examiner.

1. A DRAFTING HEAD SURFACE COMPRISING A DRAFTING HEAD SUPPORT MOVABLE INALL DIRECTIONS ON THE SURFACE OF A DRAWING BOARD WHILE MAINTAINING ALINE OF SAID SUPPORT IN PARELLEL RELATION AT ALL TIMES, A SHAFT HAVING ABORE ROTATABLY MOUNTED ON SAID SUPPORT, A DRAFTING HEAD PLATE FIXED TOSAID SHAFT, A CUP HAVING A BORE IN THE BOTTOM THEREOF MOUNTED ON SAIDSHAFT IN FIXED RELATION, A PAWLOPERATING WHEEL HAVING A BOSS PROJECTINGTHEREFROM ROTATABLY MOUNTED ON SAID CUP, SAID CUP AND SAID BOSS OF SAIDPAWL-OPERATING WHEEL BEING PROVIDED WITH SLOTS THEREIN, A DRAFTING HEADROTATING KNOB MOUNTED ON SAID CUP, A CONTROL BAR POSITIONED IN SAID CUPAND EXTENDING DIAMETRICALLY INTO THE SLOTS OF SAID CUP AND BOSS OF SAIDPAWLOPERATING WHEEL, A LEVER PIVOTALLY MOUNTED IN SAID BORE OF SAIDSHAFT AND BEING CONNECTED TO SAID CONTROL BAR, A LINK MOUNTED IN SAIDDRAFTING HEAD PLATE AND CONNECTED TO SAID LEVER, AND A PAWL OPERATIVELYCONNECTED TO SAID LINK WHEREBY SAID PAWL CAN BE OPERATED BY ROTATION OFSAID PAWL-OPERATING WHEEL, A DISC MOUNTED ON SAID DRAFTING HEAD SUPPORTFOR COOPERATION WITH SAID PAWL TO RETAIN SAID DRAFTING HEAD IN FIXEDRELATION TO SAID DRAFTING HEAD SUPPORT, A CAM PUSH-BUTTON MOUNTED ONSAID DRAFTING HEAD OPERATING KNOB HAVING ITS CAM SURFACE COOPERABLE WITHSAID LEVER IN ONE DIRECTION, AND A SPRING OPERABLE TO MOVE SAID PAWLINTO OPERATIVE POSITION WITH RESPECT TO SAID DISC.